Genetic genealogy is cracking cases once thought unsolvable. Not all police forces can afford to use it

As more police forces crack decades-old cold cases with the help of genetic genealogy, Montreal police have yet to have a major breakthrough on a case of their own.

The lack of progress — at least publicly — is raising concerns about the Montreal police department's priorities at a time when both the Sûreté du Québec and neighbouring Longueuil police have used new forensic methods to solve cases long thought to be unsolvable.

Last spring, Longueuil police solved the 1975 murder of Sharron Prior and in 2022, Quebec provincial police tracked down the man suspected of killing Guylaine Potvin, a 19-year-old slain in Saguenay nearly 24 years ago. He is now on trial for first-degree murder and sexual assault.

Both cases analyzed Y chromosome DNA — which traces paternal ancestry — to help match an unknown profile with a potential family name. Armed with new leads, police then used traditional policing techniques to zero in on a suspect.

Stéphane Luce runs a non-profit organization that raises awareness of unresolved missing persons and murder cases in Quebec. He says it's about time Montreal had a win.

The Service de police de la Ville de Montréal (SPVM) created a cold case unit in the spring of 2019 which now has eight investigators.

"With this new technology it could be a good thing for the investigators to put their nose in a file and find out if there's DNA and good DNA to be worked on," said Luce, president of Meurtres et Disparitions Irrésolus du Québec.

Luce's organization has pushed the SPVM to re-examine several unsolved murders, including that of 12-year-old Stéphane Gauthier, who was abducted and murdered just before Christmas in 1982.

Luce believes Gauthier's case is a perfect candidate for advanced genetic testing because unidentified DNA was found at the crime scene.

"The killer could lead to other murders that occurred in the 70's and 80's (in Montreal)," said Luce, who believes Gauthier's case could be solved quickly if the SPVM took it seriously.

The SPVM said it's impossible to quantify how many cases could benefit from genetic genealogy. Since the 1980s, there are hundreds of unsolved murders on its books.

In an email, a spokesperson for the department would only say the cold case unit is "actively working on a number of files related to technological advances in DNA identification."

Most recently, Montreal worked with Ontario Provincial Police to help solve the murder of Jewell Parchman Langford, a woman from Tennessee who disappeared in Montreal in 1975.

Her body was found in the Nation River near Casselman, Ont., between Montreal and Ottawa, about a month after her disappearance. But for decades, her identity remained a mystery until the OPP used genetic genealogy to find her relatives.